Currently, much of the utility of computer systems lies in their ability to communicate and share information with other computer systems. Information is typically passed between computer systems via computer networks. Computer networks are groups of computers interconnected by wires or wireless mechanisms such as infrared, radio, and other technologies. The Internet is a global network of many smaller computer networks connected to one another. There is no controlling central network, but rather several high level networks that are connected through network access points. A network access point is a computer hardware or software device (commonly a network router) that serves as a kind of translator between two different networks.
Web services, generally, refers to application-to-application communication over the Internet via programmatic interfaces. For example, a local application (e.g., Microsoft® Money) on a client computer may communicate with a server application on a remote computer to obtain stock ticker information. The two applications may communicate the requested ticker symbol and the corresponding results via one or more messages transmitted over the Internet, without opening or using a traditional Internet browser such as Internet Explorer®.
The advent of XML (eXtensible Markup Language) and other protocol-neutral communications mechanisms has made it easier for web services to be offered between computers residing on different networks, written in different languages, and/or using different operating systems, yet still communicate effectively in an interoperable manner. However, these protocol neutral mechanisms do not provide an extensible mechanism to describe metadata regarding an object, nor do present metadata description techniques allow for the refining of metadata by other metadata or allow for secure metadata statements without the use of separate encryption technologies. Web services description language (WSDL) is known, however, WSDL described web services interfaces. WSDL does not describe metadata regarding a web service, such as its communication policies, etc.
FIG. 1 illustrates metadata in a conventional HTML document, e.g., from http://www.microsoft.com. In FIG. 1, each metadata element has a name (e.g., “keywords,” “description,” etc.) and corresponding content. These metadata elements apply only to the current object, i.e., the URL http://www.microsoft.com/default.asp.
Thus, it would be an advancement in the art to provide a mechanism for describing metadata in an extensible manner. It would be a further advancement in the art to allow metadata to refer to multiple objects, messages, and/or message patterns simultaneously. It would be a further advancement in the art to provide a metadata description mechanism that allows metadata statements to be refined by subsequent metadata statements. It would be a further advancement in the art to provide secure metadata statements without using external security measures.